电子顺磁共振对五种中草药抗氧化活性的研究

采用电子顺磁共振(EPR)技术,通过大黄、香青兰、香茅草、懈寄生和骆驼蓬子五种中草药对1,1-二苯基-2-苦基肼自由基(DPPH)、羟基自由基(·OH)和超氧阴离子自由基(O-·2)3种自由基清除能力大小的比较,研究了大黄等五种中草药抗氧化活性能力。这五种中草药对3种自由基均有一定的清除作用,其中大黄清除DPPH和超氧阴离子自由基的IC50小于0.5 mg/mL,清除羟基自由基的IC50=1.892 mg/mL。结果表明五种中草药中大黄的抗氧化活性能力最强,为中草药用于生物体的抗氧化应激研究提供依据。     

十四种化合物的抗氧化活性

本文以抑制硫代巴比妥酸反应物的生成为指标,测定了十四种化合物的抗氧化活性,并估测了其中十一种化合物与-OH反应的动力学常数,发现它们的量效关系为:1.抗氧化活性与浓度成直线相关性,按其抗氧化活性由大到小排列顺序如下:N、N-二乙基硫代氨甲酸钠;4-羟基桂皮酸二乙胺基乙基醋盐酸盐;1-色氨酸;S,2(3-氨基丙基氨基)乙基硫代磷酸;S,2-氨基乙基异硫脲盐酸盐:dl-蛋氨酸;dl-组氨酸;乙醇:烟酰胺;柠檬酸钠;甘氨酸.2.抗坏血酸与1-半胱氨酸低浓度时促氧化,高浓度时抗氧化.3.还原性谷胱甘肽其抗氧化活性与浓度的关系成指数型.     

真菌多糖抗氧化活性的研究进展

真菌多糖的抗氧化作用目前正成为国内外众多学科领域研究的热点之一,对真菌子实体多糖、菌丝体多糖和胞外多糖的抗氧化活性研究现状进行了综述,并对其研究前景进行了展望,旨在为真菌多糖的进一步研究和利用提供参考.     

苏木、紫草等五种中草药抗氧化活性的研究

苏木和紫草的乙酸乙酯提取物有很强的抗氧化活性,知母、七叶一枝花、桃仁等的该种提取物抗氧化效果则较差。维生素C、酒石酸具有一定的协同增效作用。     

抗氧化活性检测方法的研究进展

本文综述了常用的抗氧化活性检测方法,讨论了各种方法的优缺点.     

枸杞子提取液抗氧化活性的研究

用Folin-Ciocalteu法、DPPH法和Fenton法分别对脱脂及未脱脂枸杞子的水和50%、80%、95%乙醇提取液的抗氧化活性进行测定。结果显示:3种方法所得结果具有一致的规律,相同提取条件下,未脱脂枸杞子的抗氧化活性大于脱脂枸杞子;随着乙醇浓度增大,枸杞子提取液的抗氧化活性逐渐减小,即水>50%乙醇>80%乙醇>95%乙醇枸杞子提取液。表明枸杞子中水溶性提取物的抗氧化活性高于脂溶性提取物;不同提取液抗氧化能力的差异说明枸杞子的抗氧化能力是枸杞子中水溶性和脂溶性多种成分协同作用的结果。     

板栗花纯露的抗氧化活性研究

以板栗花纯露清除DPPH自由基、羟基自由基和亚硝酸盐能力及其还原能力为指标,以市售两种驱蚊花露水和Vc为对照,研究板栗花纯露的抗氧化活性。当板栗花纯露浓度为0.5 mg/m L时,DPPH自由基的清除率最高,达到80.64%,IC50为0.25 mg/m L,清除率分别高于同浓度的六神(70.21%)和隆力奇花露水(60.14%)而小于Vc(90.04%)(P0.01);当浓度为0.1 mg/m L和4 mg/m L时,羟基自由基和亚硝酸盐的清除率最大,分别为74.03%和84.77%,显著高于花露水和Vc对照组(P0.01);当浓度为0.1 mg/m L时,板栗花纯露的还原力最强,但小于Vc而高于市售花露水(P0.01)。此结果证实了板栗花纯露在一定浓度范围内具有良好的抗氧化能力,将为后续板栗花纯露的开发和利用提供技术支持。     

紫草提取物的体外抗氧化活性研究

为研究紫草色素(LEP)的体外抗氧化活性,采用常规回流方法提取LEP,测定了LEP对超氧自由基(O2)和1,1-二苯基-2-苦苯肼自由基(DPPH.)的清除能力,及其对β-胡萝卜素/亚油酸自氧化体系的抑制作用。结果表明,LEP对DPPH.和O2均有较强的清除能力,并且对β-胡萝卜素/亚油酸自氧化体系有明显的抑制作用,说明紫草的药理作用可能与LEP较强的抗氧化能力有关。     

顶羽菊抗氧化活性研究

目的:探讨顶羽菊提取物的抗氧化活性。方法:采用Folin-Ciocaheu法测定顶羽菊水提物和醇提物中的多酚含量,并以芦丁为标准品测定其黄酮含量;通过总还原力测定法、Fenton法、改良的邻苯三酚自氧化法、过氧化脂质测定、亚硝酸盐清除率测定和亚硝胺合成阻断率测定,分别对顶羽菊提取物的总还原力、超氧阴离子自由基和羟自由基清除能力、脂质过氧化抑制作用、清除亚硝酸盐自由基和亚硝胺阻断率进行测定。结果:顶羽菊水提物和醇提物中含有以黄酮类为主要成分的多酚类物质;具有较强的还原性和清除超氧阴离子自由基、羟自由基的活性,且醇提物的作用高于水提物;二者对脂质过氧化的抑制率达47%以上;顶羽菊提取物具有较强的清除亚硝酸钠和阻断亚硝胺合成的能力,水提物对亚硝酸盐的最大清除率为60.4%,醇提物对亚硝胺合成的阻断率为86.6%。结论:顶羽菊醇提物可作为抗氧化剂和防癌剂,用于清除机体内自由基、抗脂质氧化、延缓机体衰老、预防心血管系统疾病和癌症的发生。     

石斛抗氧化活性研究进展

石斛作为传统的中药材,种类繁多,分布广泛,具有增强免疫力、抗氧化、抗肿瘤以及养阴生津等功效.抗氧化活性在石斛的药理功能中占据重要地位,能抑制活性氧对机体的损伤,延缓衰老,预防疾病,大量研究均围绕石斛这一特性展开.本文从抗氧化活性的石斛种、评价方法与有效成分及其作用机制三方面对石斛进行综述,以期为学者的相关研究提供最新参...     

A Novel Optimization of Water-Soluble Compound Polysaccharides from Chinese Herbal Medicines by Quantitative Theory and Study on Its Characterization and Antioxidant Activities

The present study optimized the extraction characterization and antioxidant activities of water-soluble compound polysaccharides (CPs) from hawthorn, lotus leaf, Fagopyrum tataricum, semen cassiae, Lycium barbarum, and Poria cocos Chinese herbal medicines that have mass ratios of 4 : 2 : 2 : 1.5 : 1 : 1. The CPs yield equation was predicted using quantitative theory, to which a maximum CPs yield of 7.18±0.24 % under the following optimal extraction conditions: a water-to-raw material ratio of 30 mL/g, an extraction temperature of 65 °C, an extraction time of 45 min, and extraction mode ultrasonic-assistant extraction. CPs were consisted of Ara, Gal, Glc, Xyl, Man, GalA and GlcA in a molar ratio of 3.1 : 2.6 : 50.6 : 1.7 : 20.4 : 17.2 : 4.2. The HPGPC profiles and FT-IR spectra implied that CPs were heterogeneous acidic polysaccharides and possessed the β-d -pyranose configuration. Congo red test, CD spectrum and SEM revealed that CPs with three helix conformation showed a flocculent, granulous or sheet-like appearance. Furthermore, the relationships between antioxidant activity and concentration of CPs displayed significant positive correlation, and the scavenging abilities for DPPH, hydroxyl radical, ABTS, superoxide-anion radical and reducing power of CPs were 93.56±2.51 %, 84.03±1.69 %, 83.29±1.93 %, 37.49±1.93 % and 0.467±0.006 at a concentration of 4.0 mg/mL. Therefore, CPs could be applied as a potential natural antioxidant in pharmaceutical or functional food fields.     

Cytotoxic Activity of Herbal Medicines as Assessed in Vitro: A Review

Since time immemorial, human beings have sought natural medications for treatment of various diseases. Weighty evidence demonstrates the use of chemical methodologies for sensitive evaluation of cytotoxic potentials of herbal agents. However, due to the ubiquitous use of cytotoxicity methods, there is a need for providing updated guidance for the design and development of in vitro assessment. The aim of this review is to provide practical guidance on common cell-based assays for suitable assessment of cytotoxicity potential of herbal medicines and discussing their advantages and disadvantages Relevant articles in authentic databases, including PubMed, Web of Science, Science Direct, Scopus, Google Scholar and SID, from 1950 to 2022 were collected according to selection criteria of in vitro cytotoxicity assays and protocols. In addition, the link between cytotoxicity assay selection and different factors such as the drug solvent, concentration and exposure duration were discussed.     

酿酒葡萄皮渣中白藜芦醇的抗氧化活性研究

本文利用甲醇溶剂对酿酒葡萄皮渣进行浸提,得到白藜芦醇粗提物.粗提物通过硅胶柱层析进行纯化.然后,研究了白藜芦醇的氧自由基、超氧阴离子自由基、羟自由基、DPPH自由基的清除能力.结果显示:白藜芦醇具有很强的自由基清除能力和抗氧化能力,并且随着浓度的增加,抗氧化能力增强.     

几种常用中草药抗氧化活性研究(英文)

当归、黄芪、银杏叶、益母草、野甘草是中国传统中药材,几千年来一直为中国人民所认可,在中国和世界都具有重要的科研和药用价值。本研究采用HO·清除及对肝微粒体和亚油酸脂质过氧化抑制的方法,测定五种草药精油和水煮提取物的抗氧化活性;采用Folin—Ciocalteu试剂法测定它们的总酚含量;用肝细胞体外培养法测定它们的细胞毒性并对它们的作用机制进行分析。结果发现五种草药提取物都具有一定的抗氧化活性,尤其是益母草、野甘草、银杏叶的水煮提取物活性较强,其抗氧化活性与总酚含量存在较好的线形关系。此外,本论文还为研究这些草药的一些抗病机制提供参考依据。     

毛头鬼伞(Coprinus comatus)多糖的理化性质及体外抗氧化活性

毛头鬼伞(Coprinus comatus)子实体经热水浸提、乙醇沉淀、脱蛋白和真空干燥后得到毛头鬼伞多糖。经定性化学反应和光谱鉴定,毛头鬼伞多糖不含蛋白质、核酸、酚类物质和糖醛酸,为非淀粉类中性多糖,均分子量为947 kD,完全酸水解后经气相色谱分析确定其糖基组成及其摩尔组成比为葡萄糖∶甘露糖∶半乳糖=10.5∶1.7∶1。通过对脱氧核糖体系产生的羟基自由基(.OH)的清除作用和邻苯三酚自氧化系统产生的超氧阴离子自由基(O2-.)的清除作用,对毛头鬼伞多糖体外抗氧化活性进行的研究结果表明:该多糖具有一定的抗氧化活性。     

益智的抗氧化作用

本文探讨了益智(Alpinia oxyphylla Miquel)超临界CO2提取物及其渣的水提物、正丙醇提取物和乙酸乙酯提取物的抗氧化作用,测定了总酚含量、黄酮含量、抗氧化力、还原能力、DPPH清除率.结果表明,益智超临界CO2提取物和正丙醇提取物的总酚含量最高,均为5.53%,乙酸乙酯提取物的总酚含量为4.04%,水提物总酚含量最低,为O.89%.抗氧化力与酚含量相关(R2=0.703).四种提取物中黄酮含量顺序为:乙酸乙酯提取物(6.29%)＞丙醇提取物(5.81%)＞水提取物(4.85%)＞超临界CO2提取物(4.70%).在还原能力、清除DPPH自由基和羟自由基方面,乙酸乙酯提取物表现出了很强的抗氧化能力,呈现剂量依赖关系.     

基于ORAC评价多酚类化合物抗氧化活性

采用氧自由基清除能力(ORAC)方法考察20种多酚类化合物的抗氧化活性。结果表明,该方法具有较优的线性关系(R2=0.997）;检测限(LOD）和定量限(LOQ）为0.5～3.1 μmol·L-1,精密度＜18%,准确度91%～105%。比较20种多酚类化合物抗氧化活性,对羟基苯甲酸类化合物中,鞣花酸和没食子酸具有较强的抗氧化活性;对羟基肉桂酸类以咖啡酸及其衍生物抗氧化活性最高;在类黄酮组分中,黄烷-3-醇表现出优良的抗氧化特性,黄酮醇次之。ORAC可作为评价多酚类化合物抗氧化的简便、高效的标准化检测方法。     

Metabolic Transformation of Neuropeptide Carnosine Modifies Its Biological Activity

1. The ability of carnosine and carnosine-related compounds (CRCs) to interact with several free oxygen radicals is analyzed.2. Carnosine, the CRCs (imidazole, histidine, anserine), and ergothioneine were found to be equally efficient in singlet oxygen quenching. During generation of hydroxyl radicals from hydrogen peroxide in the Fenton reaction, carnosine was found to be more effective than the CRCs tested.3. By measuring the chemiluminescence produced by carnosine and CRCs in rabbit leukocytes in the presence of luminol or lucigenin, we conclude that carnosine and other CRCs play a stimulating role in superoxide oxygen production while suppressing the myeloperoxidase system.4. ADP-induced aggregation of human platelets is slightly stimulated by carnosine but is inhibited by acetylanserine.5. The following rank order of efficiency of CRCs was demonstrated while measuring the oxidation of human serum lipoproteins: acetylcarnosine < acetylanserine < homocarnosine = ophidine < carnosine < anserine.6. The results obtained demonstrate that metabolic transformation of carnosine into CRCs in tissues may play an important role in regulating the native antioxidant status of the organism.     

Heavy metals in some Chinese herbal plants

The concentrations of nine heavy metals, cadmium, cobalt, copper, iron, manganese, nickel, lead, zinc and mercury in 42 Chinese herbal medicinal plants were determined. Generally, all the samples studied had, relative to the other trace metals, higher concentrations of iron, manganese, and zinc. The concentration range of the metals determined was comparable to that in many of the East Asian vegetables and fruits. A few samples were found to contain relatively higher concentrations of the toxic metals such as cadmium, lead, and mercury. This was probably caused by contamination during air-drying and preservation.